Package substrate, method for fabricating the same, and package device including the package substrate

ABSTRACT

A package substrate including an insulating layer having a top surface and a bottom surface opposite to the top surface, at least one first copper pattern disposed in the insulating layer and adjacent to the top surface of the insulating layer, at least one second copper pattern disposed on the bottom surface of the insulating layer, and at least one embedded aluminum pad disposed on the at least one first copper pattern, the at least one embedded aluminum pad disposed in the insulating layer such that a top surface of the at least one embedded aluminum pad is exposed by the insulating layer may be provided.

CROSS-REFERENCE TO RELATED APPLICATION

This U.S. non-provisional patent application claims priority under 35U.S.C. § 119 to Korean Patent Application No. 10-2016-0001002, filed onJan. 5, 2016, in the Korean Intellectual Property Office, the disclosureof which is hereby incorporated by reference in its entirety.

BACKGROUND

Example embodiments of the inventive concepts relate to packagesubstrates and, more particularly, to package substrates including anembedded aluminum pad to which a surface treatment process is performed,methods for fabricating the same, and package devices including thepackage substrate.

Various techniques of treating a surface of a printed circuit board(PCB) have been developed as a density of electronic componentsincreases. For example, metal plating techniques are used to treat thesurface of the PCB. The metal plating techniques may include a chemicaldeposition technique, a metal sputtering technique, an electroplatingtechnique, and an electroless metal plating technique. To cope with ademand for thin-plated and high-density PCBs, surfaces of PCBs have beenplated or electroless-treated to simplify processes of fabricating PCBsand to mitigate or remove noise from the PCBs.

Further, researches of reducing thicknesses of PCBs have been conductedas the density of electronic components increases. An insulating layerand a pattern may be formed on a coreless PCB to fabricate a thin PCB,and the thin PCB may be applied to small electronic components.Furthermore, researches have been conducted to reduce pitches in thePCBs. A total area of a PCB may be reduced by the pitch reduction. Thus,researches are being conducted for various processes such as a tentingprocess, a semi additive process (SAP), and a modified additive process(MSAP).

SUMMARY

Some example embodiments of the inventive concepts may provide packagesubstrates including an embedded aluminum pad inserted in an insulatinglayer.

Some example embodiments of the inventive concepts may also providemethods for fabricating a package substrate including an aluminum padnot protruding outside the package substrate.

According to an example embodiment, a package substrate may include aninsulating layer having a top surface and a bottom surface opposite tothe top surface, at least one first copper pattern in the insulatinglayer, the at least one first copper pattern adjacent to the top surfaceof the insulating layer, at least second copper pattern on the bottomsurface of the insulating layer, and at least one embedded aluminum padon the at least one first copper pattern, the at least one embeddedaluminum pad in the insulating layer such that a top surface of the atleast one embedded aluminum pad is exposed by the insulating layer.

According to an example embodiment, a package substrate may include aninsulating layer having a top surface and a bottom surface opposite tothe top surface, at least one first copper pattern provided in theinsulating layer, the at least one first copper pattern adjacent to thetop surface of the insulating layer, at least one second copper patternprovided in the insulating layer, the at least one second copper patternadjacent to the bottom surface of the insulating layer, at least onefirst embedded aluminum pad on the first copper pattern, the at leastone first embedded aluminum pad in the insulating layer, a top surfaceof the at least one first embedded aluminum exposed by the insulatinglayer, and at least one second embedded aluminum pad on the secondcopper pattern, the at least one second embedded aluminum pad in theinsulating layer, a bottom surface of the at least one second embeddedaluminum pad exposed by the insulating layer.

According to an example embodiment, a package device may include apackage substrate including at least one embedded aluminum pad, thepackage substrate including an insulating layer having a top surface anda bottom surface opposite to the top surface, at least one first copperpattern in the insulating layer, the first copper pattern adjacent tothe top surface of the insulating layer, and at least one second copperpattern on the bottom surface of the insulating layer, the at least oneembedded aluminum pad on the first copper pattern, the at least oneembedded aluminum pad in the insulating layer, and a top surface of theat least one embedded aluminum pad exposed by the insulating layer, anda semiconductor chip disposed on the package substrate and connected tothe package substrate through a bonding wire.

According to an example embodiment, a package substrate may include aninsulating layer including via holes, conductive vias filling the viaholes, a plurality of first metal patterns in the insulating layer, theplurality of first metal pattern adjacent to a top surface of theinsulating layer, the plurality of first metal pattern predominantlyincluding copper, a plurality of second metal patterns in the insulatinglayer, the plurality of second metal patterns adjacent to a bottomsurface of the insulating layer, the plurality of second metal patternpredominantly including copper, and at least one first embedded metalpad on at least one of the plurality of first metal patterns, the atleast one first embedded metal pad in the insulating layer such that atop surface of the at least one first embedded metal pad is exposed bythe insulating layer, the at least one first embedded metal padpredominantly including aluminum

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concepts will become more apparent in view of the attacheddrawings and accompanying detailed description.

FIG. 1 is a cross-sectional view illustrating a package substrateaccording to some example embodiments of the inventive concepts.

FIGS. 2A to 2J are cross-sectional views illustrating a method forfabricating the package substrate of FIG. 1.

FIGS. 3 and 4 are enlarged cross-sectional views of a region ‘III’ ofFIG. 1.

FIG. 5 is a cross-sectional view illustrating a package substrateaccording to some example embodiments of the inventive concepts.

FIGS. 6A to 6F are cross-sectional views illustrating a method forfabricating the package substrate of FIG. 5.

FIGS. 7 and 8 are enlarged cross-sectional views of a region ‘VII’ ofFIG. 5.

FIGS. 9 and 10 are cross-sectional views illustrating package substratesaccording to some example embodiments of the inventive concepts.

FIG. 11 is a cross-sectional view illustrating a package deviceincluding a package substrate according to some example embodiments ofthe inventive concepts.

DETAILED DESCRIPTION

FIG. 1 is a cross-sectional view illustrating a package substrateaccording to some example embodiments of the inventive concepts.

Referring to FIG. 1, a package substrate 1 may include an insulatinglayer 100, interconnection patterns 200, at least one embedded aluminumpad 300, and protection layers 400 and 450.

The insulating layer 100 may have a top surface 100 a and a bottomsurface 100 b opposite to the top surface 100 a. The insulating layer100 may include a first insulating layer 110 and a second insulatinglayer 120. The first insulating layer 110 and the second insulatinglayer 120 may be prepreg. The first insulating layer 110 may be disposedon the second insulating layer 120.

The interconnection patterns 200 may be disposed in the insulating layer100. The interconnection pattern 200 may include a first copper pattern210, a second copper pattern 220, a third copper pattern 230, a firstvia 240, and a second via 250. The first copper pattern 210 may bedisposed in the first insulating layer 110 and may be adjacent to thetop surface 100 a of the insulating layer 100. The second copper pattern220 may be disposed on the second insulating layer 120 (e.g., on thebottom surface 100 b of the insulating layer 100). The second copperpattern 220 may have a bottom surface 220 a and a sidewall 220 b. Thethird copper pattern 230 may be disposed in the second insulating layer120 and may be disposed between the first copper pattern 210 and thesecond copper pattern 220. The first via 240 may connect at least onefirst copper pattern 210 to at least one third copper pattern 230. Thesecond via 250 may connect at least one second copper pattern 220 to atleast one third copper pattern 230. For example, the first via 240 andthe second via 250 may include copper (Cu). However, example embodimentsof the inventive concepts are not limited to a specific arrangement ofthe interconnection patterns 200.

The embedded aluminum pad 300 may be disposed on the first copperpattern 210 and may be in contact with the first copper pattern 210. Theembedded aluminum pad 300 may be provided in plurality in each of bothedge portions of the first insulating layer 110. The plurality ofembedded aluminum pads 300 disposed in one edge portion of the firstinsulating layer 110 may be spaced apart from each other, and theplurality of embedded aluminum pads 300 disposed in another edge portionof the first insulating layer 300 may be spaced apart from each other.The embedded aluminum pad 300 may be inserted in the first insulatinglayer 110 and may not protrude outside the first insulating layer 110.The embedded aluminum pad 300 may have a top surface 300 a exposed bythe insulating layer 100. In some example embodiments, the top surface300 a of the embedded aluminum pad 300 may be disposed at the same levelas the top surface 100 a of the insulating layer 100.

The protection layers 400 and 450 may include a first protection layer400 disposed on the top surface 100 a of the insulating layer 100 and asecond protection layer 450 disposed on the bottom surface 100 b of theinsulating layer 100. The first protection layer 400 may have openings420 exposing the embedded aluminum pads 300 disposed in the both edgeportions of the first insulating layer 110. As described above, thesecond protection layer 450 may be disposed on the bottom surface 100 bof the insulating layer 100. The second protection layer 450 may coverthe sidewall 220 b of the second copper pattern 220 and may expose thebottom surface 220 a of the second copper pattern 220. The firstprotection layer 400 may protect the first copper patterns 210 and maymitigate or prevent a bridge phenomenon from occurring between the firstcopper patterns 210 adjacent to each other. The second protection layer450 may protect the second copper patterns 220 and may mitigate orprevent a bridge phenomenon from occurring between the second copperpatterns 220 adjacent to each other. Each of the first and secondprotection layers 400 and 450 may be an insulating coating layer. Forexample, the insulating coating layer may include epoxy resin.

A coating layer 500 may cover the bottom surface 220 a of the secondcopper pattern 220 and may cover a portion of the second protectionlayer 450. The coating layer 500 may mitigate or prevent oxidation ofthe second copper pattern 220. For example, the coating layer 500 mayinclude an organic compound including one of a chloride or a fluoride.

According to some example embodiments of the inventive concepts, theembedded aluminum pad 300 may not protrude outside the first insulatinglayer 110 but may be disposed in the first insulating layer 110. Ingeneral, a package substrate may have a pad protruding outward. Adistance between the embedded aluminum pads 300 according to theinventive concepts may be greater than a distance between general pads.Thus, the embedded aluminum pads 300 may not be in contact with eachother, and reliability may be improved in a wire bonding process of thepackage substrate 1.

According to some example embodiments of the inventive concepts, asurface finishing process may be performed using aluminum (Al) as a pad.Aluminum (Al) may have a desirable electrical conductivity and may beinexpensive. Thus, aluminum (Al) may be substituted for gold (Au) in anelectroless nickel/immersion gold (ENIG) process. Thus, a fabricationcost of the package substrate 1 may be substantially reduced.

FIGS. 2A to 2J are cross-sectional views illustrating a method forfabricating the package substrate of FIG. 1.

Referring to FIG. 2A, a carrier substrate 10 may be provided. A copperfoil 11 and a release layer 12 may be sequentially stacked on each ofboth surfaces (e.g., top and bottom surfaces) of the carrier substrate10. An aluminum seed layer 380 may be provided on the release layers 12of the carrier substrate 10. Thin barrier metals such as copper may beplaced between the release layers 12 and the aluminum seed layer 380 formitigating IMC formation and selective etching. The carrier substrate 10may have a structure in which a plurality of insulating material layersmay be stacked. Each of the insulating material layers may include resinor glass fiber. The release layer 12 may include an alloy or an organiccompound. The aluminum seed layer 380 may be formed by, for example, adeposition process or a plating process. Thin seed Cu may be depositedor plated on the aluminum seed layer 380 for improved plating.

Referring to FIG. 2B, a mask pattern 20 exposing one or more portions ofthe aluminum seed layer 380 may be provided on each of the aluminum seedlayers 380. Subsequent processes will be performed on the both surfaces(e.g., the top surface and bottom surface) of the carrier substrate 10in symmetry with respect to the carrier substrate 10.

Referring to FIG. 2C, one or more first copper patterns 210 may beformed using the mask pattern 20 on the aluminum seed layer 380. Thefirst copper pattern 210 may be formed on the aluminum seed layer 380 oneach of the both surfaces of the carrier substrate 10. The first copperpattern 210 may be formed by a plating process.

Referring to FIG. 2D, the aluminum seed layer 380 may be etched usingthe first copper pattern 210 as an etch mask to form a preliminaryaluminum pad 330. An etching solution used in the etching process mayinclude a material that does not react with copper (Cu) but reacts withaluminum (Al). For example, the etching solution may include an alkalineetching solution including sodium hydroxide (NaOH), or an acid etchingsolution in which an organic acid is mixed with phosphoric acid (H₃PO₄)and sulfuric acid (H₂SO₄). A width of the preliminary aluminum pad 330formed by the etching process may be similar to a width of the firstcopper pattern 210. The copper foil 11 and the release layer 12 may alsobe patterned by the etching process. Even though the copper foil 11 isformed of copper, a portion of the copper foil 11 may be removed by theetching process because the copper foil 11 has a very thin thickness.

Referring to FIG. 2E, a first insulating layer 110 may be formed tocover the first copper pattern 210 and the preliminary aluminum pad 330.As illustrated in FIG. 2E, the first insulating layer 110 may be formedon each of the both surfaces of the carrier substrate 10. The firstinsulating layer 110 may be in contact with the release layer 12 on onesurface of the first insulating layer 110, and a metal layer 30 may beprovided on another surface of the first insulating layer 110. The firstinsulating layer 110 may be prepreg.

Referring to FIG. 2F, a first via-hole 245 may be formed to expose thefirst copper pattern 210. The first via-hole 245 may penetrate a portionof the first insulating layer 110, which is disposed between the metallayer 30 and the first copper pattern 210. Further, the first via-hole245 may also penetrate the metal layer 30 overlapping with the firstcopper pattern 210. The first via-hole 245 may be formed by a laserdrilling process.

Referring to FIG. 2G, a plating process may be performed to form a firstvia 240 and a third preliminary copper pattern 235. The first via 240may fill the first via-hole 245. The third preliminary copper pattern235 may be formed on the first insulating layer 110. The first via 240and the third preliminary copper pattern 235 may be plated with the samemetal material. For example, the metal material may be copper (Cu).

Referring to FIG. 2H, the third preliminary copper pattern 235 may beetched to form a third copper pattern 230. An etching solution used inthe etching process may include a mixed solution of ammonium hydroxideand hydrogen peroxide or a mixed solution of hydrogen peroxide andsulfuric acid. A plurality of the third copper patterns 230 may bespaced apart from each other on the first insulating layer 110.

Referring to FIG. 2I, a second insulating layer 120, a second copperpattern 220, and a second via 250 may be formed. Further, the secondinsulating layer 120 may cover the third copper pattern 230 and may bein contact with the first insulating layer 110. The second insulatinglayer 120 may be prepreg. Similarly to FIG. 2G, a second via-hole 255exposing the third copper pattern 230 may be formed to penetrate aportion of the second insulating layer 120. The second via-hole 255 maybe formed by a laser drilling process. A plating process may beperformed to form the second via 250 filling the second via-hole 255 andthe second copper pattern 220 disposed on the second insulating layer120. The second via 250 may connect the second copper pattern 220 to thethird copper pattern 230. The first copper pattern 210, the secondcopper pattern 220, the third copper pattern 230, the first via 240, andthe second via 250 may be formed of the same metal material. Forexample, the metal material may be copper (Cu). The second copperpattern 220 may be formed in plurality, and the plurality of secondcopper patterns 220 may be spaced apart from each other on the secondinsulating layer 120.

Referring to FIG. 2J, the carrier substrate 10, the copper foil 11, andthe release layer 12 may be removed. A first protection layer 400 may beformed on a top surface 100 a of an insulating layer 100 including thefirst and second insulating layers 110 and 120, and a second protectionlayer 450 may be formed on a bottom surface 100 b of the insulatinglayer 100. Because the release layer 12 is easily separated from thepreliminary aluminum pads 330, the carrier substrate 10, the copper foil11, and the release layer 12 may be easily removed.

The first protection layer 400 may be formed to cover the top surface100 a of the insulating layer 100. The first protection layer 400 mayhave openings 420 exposing top surfaces 300 of the preliminary aluminumpads 330 disposed at edges of the first insulating layer 110. Thepreliminary aluminum pad 330 exposed by the opening 420 and the firstinsulating layer 110 may be defined as an embedded aluminum pad 300. Anunexposed preliminary aluminum pad 330 covered by the first protectionlayer 400 may not be removed. Because a thickness of the unexposedpreliminary aluminum pad 330 is much smaller than that of the firstcopper pattern 210, the unexposed preliminary aluminum pad 330 may notinfluence electrical characteristics of a package substrate 1 eventhough it is not removed. For example, the thickness of the preliminaryaluminum pad 330 may range from 0.1 μm to 1 μm. Further, because thefirst protection layer 400 is easily bonded to the preliminary aluminumpad 330, the first protection layer 400 may be easily fixed on the firstinsulating layer 110 by the preliminary aluminum pad 330.

The second protection layer 450 may expose a bottom surface 220 a of thesecond copper pattern 220 and may cover a sidewall 220 b of the secondcopper pattern 220 and the bottom surface 100 b of the insulating layer100. A coating layer 500 may be formed on the bottom surface 220 a ofthe second copper pattern 220. For example, the coating layer 500 mayinclude an organic compound including one of a chloride or a fluoride.Further, the coating layer 500 may be formed by a substitution reactionbetween the organic compound and a portion of the second copper pattern200 or may be formed by a coating process using the organic compound.The coating layer 500 may be formed to fabricate the package substrate1.

According to the present example embodiment, aluminum (Al) may be usedas a seed layer of the plating process for forming the first copperpattern 210. The aluminum (Al) used as the seed layer may not be removedbut may be used as the pad of the package substrate 1 in a subsequentprocess. Thus, the processes of fabricating the package substrate 1 maybe simplified. Further, because an additional surface treatment processof the first copper pattern 210 is not needed, a fabrication cost of thepackage substrate 1 may be reduced.

FIGS. 3 and 4 are enlarged cross-sectional views of a region ‘III’ ofFIG. 1. Hereinafter, the descriptions to the same technical features asmentioned above will be omitted or mentioned briefly for ease andconvenience of explanation.

Referring to FIGS. 1 and 3, the embedded aluminum pads 300 may bedisposed on the first copper patterns 210, respectively. The embeddedaluminum pad 300 may be provided in plurality in each of both edgeportions of the first insulating layer 110. The first copper patterns210 and the embedded aluminum pads 300 may have the same width W0. Thefirst copper patterns 210 may be spaced apart from each other by a firstdistance d1. The embedded aluminum pads 300 may be spaced apart fromeach other by a second distance d2. The first distance d1 may be equalto the second distance d2.

Because the embedded aluminum pads 300 are inserted in the firstinsulating layer 110, the package substrate 1 may be fabricated suchthat the second distances d2 between the embedded aluminum pads 300 areuniform. Further, the distance between the embedded aluminum pads 300according to the inventive concepts may be greater than a distancebetween pads protruding from an insulating layer in a general packagesubstrate. Thus, reliability of a process of bonding a semiconductorchip to the package substrate 1 may be improved.

Referring to FIGS. 1 and 4, an aluminum oxide layer 310 may be providedon each of the embedded aluminum pads 300, and a barrier layer 320 maybe disposed between each of the embedded aluminum pads 300 and arespective one of the first copper patterns 210. Because the embeddedaluminum pads 300 come in contact with air, the aluminum oxide layers310 may be naturally formed. The aluminum oxide layers 310 may mitigateor prevent additional oxidation and color change of the embeddedaluminum pads 300. The aluminum oxide layer 310 may have a top surface310 a exposed outside the first insulating layer 110, and the topsurface 310 a of the aluminum oxide layer 310 may be disposed at thesame level as the top surface 100 a of the insulating layer 100. Forexample, the aluminum oxide layer 310 may be formed of alumina (Al₂O₃).The barrier layer 320 may mitigate or prevent copper (Cu) from beingdiffused from the first copper pattern 210 into the embedded aluminumpad 300. If copper (Cu) is diffused into the embedded aluminum pad 300,electrical conductivity of the embedded aluminum pad 300 may be reduced.According to the present example embodiment, the electrical conductivityof the embedded aluminum pads 300 may be maintained by the barrierlayers 320. For example, the barrier layer 320 may include at least oneof nickel (Ni), titanium (Ti), tantalum (Ta), titanium nitride (TiN),tantalum nitride (TaN), gold (Au), silver (Ag), or tungsten (W). In someexample embodiments, the barrier layer 320 may include nickel (Ni).

The first copper patterns 210 may be spaced apart from each other by afirst distance d1. The embedded aluminum pads 300 may be spaced apartfrom each other by a second distance d2, the aluminum oxide layers 310may be spaced apart from each other by the second distance d2, and thebarrier layers 320 may be spaced apart from each other by the seconddistance d2. The first distance d1 may be equal to the second distanced2.

FIG. 5 is a cross-sectional view illustrating a package substrateaccording to some example embodiments of the inventive concepts.Hereinafter, the descriptions to the same elements as in the exampleembodiment of FIG. 1 will be omitted or mentioned briefly for ease andconvenience of explanation.

Referring to FIG. 5, a package substrate 1 may include an insulatinglayer 100, an interconnection pattern 200, an embedded aluminum pad 300,and protection layers 400 and 450.

The insulating layer 100 may include a first insulating layer 110 and asecond insulating layer 120. The first insulating layer 110 may have arecess region 150 that is recessed in a direction from a top surface 100a of the insulating layer 100 toward a bottom surface 100 b of theinsulating layer 100. The recess region 150 may be provided inplurality.

The interconnection pattern 200 may be disposed in the insulating layer100. The interconnection pattern 200 may include a first copper pattern210, a second copper pattern 220, a third copper pattern 230, a firstvia 240, and a second via 250.

The embedded aluminum pad 300 may be disposed on the first copperpattern 210. A width of the embedded aluminum pad 300 may be smallerthan a width of the first copper pattern 210. Likewise, a width of therecess region 150 may be smaller than the width of the first copperpattern 210.

The protection layers 400 and 450 may include a first protection layer400 disposed on the top surface 100 a of the insulating layer 100 and asecond protection layer 450 disposed on the bottom surface 100 b of theinsulating layer 100. The first protection layer 400 may include atleast one protrusion 410 that protrudes downward from top surface 100 aof the insulating layer 100 toward the bottom surface 100 b of theinsulating layer 100 so as to be in contact with the first copperpattern 210 covered by the first protection layer 400. In other words,the protrusion 410 may be disposed in the recess region 150. A width ofthe protrusion 410 may be smaller than the width of the first copperpattern 210. The first protection layer 400 may have openings 420exposing the embedded aluminum pads 300 disposed in the both edgeportions of the first insulating layer 110. As described above, thesecond protection layer 450 may be disposed on the bottom surface 100 bof the insulating layer 100. The second protection layer 450 may coverthe sidewall 220 b of the second copper pattern 220 and may expose thebottom surface 220 a of the second copper pattern 220. The firstprotection layer 400 may protect the first copper patterns 210 and maymitigate or prevent a bridge phenomenon from occurring between adjacentones of the first copper patterns 210. The second protection layer 450may protect the second copper patterns 220 and may mitigate or prevent abridge phenomenon from occurring between adjacent ones of the secondcopper patterns 220. Each of the first and second protection layers 400and 450 may be an insulating coating layer. For example, the insulatingcoating layer may include epoxy resin.

FIGS. 6A to 6F are cross-sectional views illustrating a method forfabricating the package substrate of FIG. 5. In the present exampleembodiment, the descriptions to the same elements or technical featuresas in the example embodiment of FIGS. 2A to 2J will be omitted ormentioned briefly for ease and convenience of explanation.

Referring to FIG. 6A, a copper foil 11, a release layer 12, and analuminum seed layer 380 may be provided on each of both surfaces of acarrier substrate 10. First copper patterns 210 may be formed on each ofthe aluminum seed layers 380 by a plating process.

Referring to FIG. 6B, preliminary aluminum pads 330 may be formed by anetching process. An etching solution used in the etching process may notreact with copper (Cu) but may react with aluminum (Al). However,because the copper foil 11 has a very thin thickness, a portion of thecopper foil 11 may be removed by the etching process. The preliminaryaluminum pad 330 may be etched by the etching process such that a widthof the preliminary aluminum pad 330 is smaller than a width of the firstcopper pattern 210.

Referring to FIG. 6C, a first insulating layer 110 may be formed tocover the first copper pattern 210 and the preliminary aluminum pad 330.The first insulating layer 110 may be drilled to form a first via-hole245 exposing a portion of the first copper pattern 210.

Referring to FIG. 6D, a plating process may be performed to form a firstvia 240 filling the first via-hole 245 and a third copper pattern 230disposed on the first insulating layer 110.

Referring to FIG. 6E, a second insulating layer 120, a second copperpattern 220, and a second via 250 may be formed. Thereafter, the carriersubstrate 10, the copper foil 11, and the release layer 12 which are incontact with the first insulating layer 110 and the preliminary aluminumpads 330 may be removed, and one or some of the preliminary aluminumpads 330 may be removed. The one or some of the preliminary aluminumpads 330 may be removed by an etching process. An etching solution usedin the etching process of removing the one or some preliminary aluminumpads 330 may include, for example, a mixed solution of ammoniumhydroxide and hydrogen peroxide or a mixed solution of hydrogen peroxideand sulfuric acid. Spaces formed by the removal of the one or somepreliminary aluminum pads 330 may be defined as recess regions 150. Therecess region 150 may be recessed or depressed in a direction from thetop surface 100 a of the insulating layer 100 toward the bottom surface100 b of the insulating layer 100.

Referring to FIG. 6F, a first protection layer 400 may be formed on thetop surface 100 a of the insulating layer 100, and a second protectionlayer 450 may be formed on the bottom surface 100 b of the insulatinglayer 100. The first protection layer 400 may be formed to cover the topsurface 100 a of the insulating layer 100 and the recess regions 150.The first protection layer 400 may have an opening 420 exposing at leastone preliminary aluminum pad 330 that is not removed. The preliminaryaluminum pad 330 exposed by the opening 420 may be defined as anembedded aluminum pad 300. The embedded aluminum pad 300 may be providedin plurality in each of both edge portions of the first insulating layer110. The first protection layer 400 may be formed to cover the topsurface 100 a of the insulating layer 100, and the second protectionlayer 450 may be formed to cover the bottom surface 100 b of theinsulating layer 100. The first protection layer 400 may have at leastone protrusion 410, and the protrusion 410 may fill the recess region150.

FIGS. 7 and 8 are enlarged cross-sectional views of a region ‘VII’ ofFIG. 5.

Referring to FIGS. 5 and 7, the first copper pattern 210 may have afirst width W1, and the embedded aluminum pad 300 may have a secondwidth W2. The first copper pattern 210 may have a greater width than theembedded aluminum pad 300. In other words, the first width W1 may begreater than the second width W2.

The embedded aluminum pad 300 may be provided in plurality in each ofboth edge portions of the first insulating layer 100. The plurality ofembedded aluminum pads 300 may be disposed on a plurality of the firstcopper patterns 210, respectively. The first copper patterns 210 may bespaced apart from each other by a first distance d1, and the embeddedaluminum pads 300 may be spaced apart from each other by a thirddistance d3. The third distance d3 may be greater than the firstdistance d1.

Referring to FIGS. 5 and 8, an aluminum oxide layer 310 may be providedon each of the embedded aluminum pads 300, and a barrier layer 320 maybe disposed between each of the first copper patterns 210 and acorresponding one of the embedded aluminum pads 300. The aluminum oxidelayer 310 may have a top surface 310 a exposed outside the firstinsulating layer 110, and the top surface 310 a of the aluminum oxidelayer 310 may be disposed at the same level as the top surface 100 a ofthe insulating layer 100. For example, the aluminum oxide layer 310 mayinclude alumina (Al₂O₃), and the barrier layer 320 may include at leastone of nickel (Ni), titanium (Ti), tantalum (Ta), titanium nitride(TiN), tantalum nitride (TaN), gold (Au), silver (Ag), or tungsten (W).In some example embodiments, the barrier layer 320 may include nickel(Ni).

The first copper patterns 210 may be spaced apart from each other by afirst distance d1. The embedded aluminum pads 300 may be spaced apartfrom each other by a third distance d3, the aluminum oxide layers 310may be spaced apart from each other by the third distance d3, and thebarrier layers 320 may be spaced apart from each other by the thirddistance d3. The third distance d3 may be greater than the firstdistance d1.

FIGS. 9 and 10 are cross-sectional views illustrating package substratesaccording to some example embodiments of the inventive concepts.Hereinafter, the descriptions to the same elements as in the exampleembodiment of FIG. 1 will be omitted or mentioned briefly for ease andconvenience of explanation.

Referring to FIG. 9, an insulating layer 100 may have a top surface 100a and a bottom surface 100 b opposite to the top surface 100 a. A firstrecess region 150 recessed or depressed toward the bottom surface 100 bmay be provided at the top surface 100 a of the insulating layer 100,and a second recess region 160 recessed or depressed toward the topsurface 100 a may be provided at the bottom surface 100 b of theinsulating layer 100.

An interconnection pattern 200 may include a first copper pattern 210adjacent to the top surface 100 a of the insulating layer 100 and asecond copper pattern 220 adjacent to the bottom surface 100 b of theinsulating layer 100. A via 260 may connect at least one first copperpattern 210 to at least one second copper pattern 220.

A first embedded aluminum pad 300 may be disposed on the first copperpattern 210, and a second embedded aluminum pad 350 may be disposed onthe second copper pattern 220. The first embedded aluminum pad 300 andthe second embedded aluminum pad 350 may be disposed in the insulatinglayer 100. The first embedded aluminum pad 300 may have a top surface300 a exposed outside the insulating layer 100, and the second embeddedaluminum pad 350 may have a bottom surface 350 a exposed outside theinsulating layer 100. The top surface of the first embedded aluminum pad300 may be disposed at the same level as the top surface 100 a of theinsulating layer 100, and the bottom surface 350 a of the secondembedded aluminum pad 350 may be disposed at the same level as thebottom surface 100 b of the insulating layer 100. In other words, thefirst embedded aluminum pad 300 and the second embedded aluminum pad 350may not protrude outside the insulating layer 100.

A first protection layer 400, which is disposed on the top surface 100 aof the insulating layer 100, may have a first protrusion 410 protrudingin a direction from the top surface 100 a of the insulating layer 100toward the bottom surface 100 b of the insulating layer 100, and mayhave a first opening 420 exposing at least one first embedded aluminumpad 300. A second protection layer 450, which is disposed on the bottomsurface 100 b of the insulating layer 100, may have a second protrusion460 protruding in a direction from the bottom surface 100 b of theinsulating layer 100 toward the top surface 100 a of the insulatinglayer 100, and may have a second opening 480 exposing at least onesecond embedded aluminum pad 350. The first protrusion 410 may fill thefirst recess region 150, and the second protrusion 460 may fill thesecond recess region 160.

Referring to FIG. 10, the embedded aluminum pads 300 may be variouslyarranged. In some example embodiments, the embedded aluminum pads 300may be provided in both edge portions of the insulating layer 100, andone embedded aluminum pad 300 may be provided in each of the both edgeportions of the insulating layer 100. The arrangement of the embeddedaluminum pads 300 may be variously modified according to a semiconductorchip (not shown) mounted on the package substrate 1.

The package substrates 1 of FIGS. 9 and 10 may be fabricated by a methodsimilar to the fabrication method described with reference to FIGS. 2Ato 2J.

FIG. 11 is a cross-sectional view illustrating a package deviceincluding a package substrate according to some example embodiments ofthe inventive concepts. Hereinafter, the descriptions to the sameelements as in the example embodiment of FIG. 1 will be omitted ormentioned briefly for ease and convenience of explanation.

Referring to FIG. 11, a semiconductor package (or a package device) 1000may include the package substrate 1, a semiconductor chip 500, and amold layer 700.

The semiconductor chip 500 may be disposed on the package substrate 1.The semiconductor chip 500 may be disposed on the first protection layer400 of the package substrate 1. The semiconductor chip 500 may be alogic chip, a memory chip, or a combination thereof. An adhesive layer550 may be provided between the semiconductor chip 500 and the packagesubstrate 1.

A bonding wire 600 may electrically connect the package substrate 1 tothe semiconductor chip 500. For example, the bonding wire 600 may beformed of copper (Cu) or gold (Au). The bonding wire 600 mayelectrically connect the semiconductor chip 500 to the embedded aluminumpad 300 of the package substrate 1. Aluminum (Au) may have excellentelectrical conductivity but may have an oxidation characteristic. Thebonding wire 600 may penetrate the aluminum oxide layer 310 by a stitchbonding process so as to be directly connected to the embedded aluminumoxide layer pad 300.

The mold layer 700 may cover the semiconductor chip 500. The mold layer700 may include an insulating polymer material such as an epoxy moldingcompound (EMC).

According to some example embodiments of the inventive concepts, the padof the package substrate may be formed of low-priced aluminum, therebyreducing the fabrication cost of the package substrate.

According to some example embodiments of the inventive concepts, thepackage substrate of which the surface is treated using aluminum may bebonded to the semiconductor chip by the bonding wire. The bonding wiremay penetrate the oxide layer formed on the embedded aluminum pad toelectrically connect the embedded aluminum pad to the semiconductorchip.

According to some example embodiments of the inventive concepts, thealuminum pad may not protrude outside the package substrate, and thusthe thickness of the package substrate may be reduced. Further, aplurality of the embedded aluminum pads may be inserted in theinsulating layer such that the distance between adjacent ones of theembedded aluminum pads is increased. Thus, reliability of the wirebonding process may be improved.

While the inventive concepts have been described with reference to someexample embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirits and scopes of the inventive concepts. Therefore, itshould be understood that the above example embodiments are notlimiting, but illustrative. Thus, the scopes of the inventive conceptsare to be determined by the broadest permissible interpretation of thefollowing claims and their equivalents, and shall not be restricted orlimited by the foregoing description.

The invention claimed is:
 1. A package substrate comprising: aninsulating layer having a top surface and a bottom surface opposite tothe top surface; at least one first copper pattern in the insulatinglayer, the at least one first copper pattern adjacent to the top surfaceof the insulating layer; at least one second copper pattern on thebottom surface of the insulating layer; and at least one embeddedaluminum pad on the at least one first copper pattern, the at least oneembedded aluminum pad in the insulating layer such that a top surface ofthe at least one embedded aluminum pad is exposed by the insulatinglayer, wherein the top surface of the at least one embedded aluminum padis at a same level as the top surface of the insulating layer, and theat least one embedded aluminum pad is on top of the at least one firstcopper pattern.
 2. The package substrate of claim 1, wherein: the atleast one first copper pattern includes a plurality of first copperpatterns; and the at least one embedded aluminum pad includes aplurality of embedded aluminum pads.
 3. The package substrate of claim2, wherein a distance between adjacent ones of the plurality of embeddedaluminum pads is equal to or greater than a distance betweencorresponding adjacent ones of the plurality of first copper patterns.4. The package substrate of claim 2, wherein a width of each of theplurality of embedded aluminum pads is equal to or smaller than a widthof a corresponding one of the plurality of first copper patterns.
 5. Thepackage substrate of claim 1, further comprising: a first protectionlayer on the top surface of the insulating layer, the first protectionlayer having an opening exposing the at least one embedded aluminum pad;and a second protection layer on the bottom surface of the insulatinglayer, the second protection layer exposing a bottom surface of the atleast one second copper pattern.
 6. The package substrate of claim 5,wherein the at least one embedded aluminum pad is in the opening.
 7. Thepackage substrate of claim 5, wherein: the at least one embeddedaluminum pad includes a plurality of embedded aluminum pads; two or moreof the plurality of embedded aluminum pads are in each of both edgeportions of the insulating layer; and the first protection layer exposesthe embedded aluminum pads, which is in the both edge portions of theinsulating layer.
 8. The package substrate of claim 5, wherein: the atleast one first copper pattern includes a plurality of first copperpatterns; at least one of the plurality of first copper patterns iscovered by the first protection layer; and the first protection layerhas at least one protrusion that protrudes from the top surface of theinsulating layer toward the bottom surface of the insulating layer suchthat the at least one protrusion is in contact with a corresponding oneof the plurality of first copper patterns.
 9. The package substrate ofclaim 5, further comprising: a coating layer covering the bottom surfaceof the at least one second copper pattern.
 10. The package substrate ofclaim 1, further comprising: a barrier layer between the at least oneembedded aluminum pad and the at least one first copper pattern, whereinthe barrier layer includes at least one of nickel (Ni), titanium (Ti),tantalum (Ta), titanium nitride (TiN), tantalum nitride (TaN), gold(Au), silver (Ag), or tungsten (W).
 11. The package substrate of claim1, further comprising: an aluminum oxide layer on the top surface of theembedded aluminum pad, the aluminum oxide layer exposed by theinsulating layer, a top surface of the aluminum oxide layer at a samelevel as the top surface of the insulating layer.
 12. A packagesubstrate comprising: an insulating layer including via holes;conductive vias filling the via holes; a plurality of first metalpatterns in the insulating layer, the plurality of first metal patternadjacent to a top surface of the insulating layer, the plurality offirst metal pattern predominantly including copper; a plurality ofsecond metal patterns in the insulating layer, the plurality of secondmetal patterns adjacent to a bottom surface of the insulating layer, theplurality of second metal pattern predominantly including copper; and atleast one first embedded metal pad on at least one of the plurality offirst metal patterns, the at least one first embedded metal pad in theinsulating layer such that a top surface of the at least one firstembedded metal pad is exposed by the insulating layer, the at least onefirst embedded metal pad predominantly including aluminum, wherein thetop surface of the at least one first embedded metal pad is at a samelevel as the top surface of the insulating layer, and the at least onefirst embedded metal pad is on top of the at least one of the pluralityof first metal patterns.
 13. The package substrate of claim 12, whereinthe at least one first embedded metal pad includes two or more firstembedded metal pads.
 14. The package substrate of claim 13, wherein adistance between adjacent ones of the two or more first embedded metalpads is equal to or greater than a distance between correspondingadjacent ones of the plurality of first metal patterns.
 15. The packagesubstrate of claim 12, further comprising: a first protection layer onthe top surface of the insulating layer, the first protection layerhaving an opening exposing the at least one first embedded metal pad.16. The package substrate of claim 15, wherein the at least one firstembedded metal pad are not provided on the plurality of first metalpatterns, which are embedded in the insulating layer and located underthe first protection layer.
 17. A package substrate comprising: aninsulating layer having a top surface and a bottom surface opposite tothe top surface; at least one first copper pattern in the insulatinglayer, the at least one first copper pattern being adjacent to the topsurface of the insulating layer; at least one second copper pattern onthe bottom surface of the insulating layer; at least one embeddedaluminum pad on the at least one first copper pattern, the at least oneembedded aluminum pad being in the insulating layer such that a topsurface of the at least one embedded aluminum pad is exposed by theinsulating layer; and a first protection layer on the top surface of theinsulating layer, the first protection layer exposing the top surface ofthe at least one embedded aluminum pad, wherein a top surface of the atleast one first copper pattern is positioned at a level lower than abottom surface of the first protection layer.
 18. The package substrateof claim 17, wherein a bottom surface of the at least one embeddedaluminum pad is lower than the bottom surface of the first protectionlayer.
 19. The package substrate of claim 17, wherein the firstprotection layer is in contact with the top surface of the insulatinglayer.
 20. The package substrate of claim 17, further comprising: asecond protection layer on the bottom surface of the insulating layer,the second protection layer exposing a bottom surface of the at leastone second copper pattern.